search for: i8rr

Hi, I am wondering how to specify the selection DAG patterns for instructions that use accumulator. For example multiply-accumulate instruction with one destination operand and two source operands: mac $dst, $src1, $src2 ;; $dst += $src1*$src2 Seems that it has a cycle in the pattern. So how do I specify it in the DAG? There are a few instructions in the ARM backend like this one, but the

Dear, I am looking at the Instructions defined in the XXXXInstrInfo.td where I can see a def record defined like below def ADD8rr : I8rr<0x0, (outs GR8:$dst), (ins GR8:$src, GR8:$src2), "add.b\t{$src2, $dst}", [(set GR8:$dst, (*add *GR8:$src, GR8:$src2)), (implicit SRW)]>; Now here I would like the to replace the add(highlighted) by an arbi...